Clay mineral surface hydration intercalation inhibitors for drilling fluids, their preparation methods, and applications

Abstract

This invention belongs to the field of drilling fluid inhibitors, and discloses a clay mineral surface hydration intercalation inhibitor for drilling fluids, its preparation method, and its application. The intercalation inhibitor contains a compound of formula A with the following structure: This intercalation inhibitor can effectively solve the technical problem that existing intercalation inhibitors cannot completely inhibit the surface hydration of clay minerals.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of drilling fluid inhibitors, and relates to a clay mineral surface hydration intercalation inhibitor for drilling fluids and a preparation method and application thereof. BACKGROUND

[0002] In oil and gas drilling engineering, wellbore instability is a long-standing problem that has plagued the industry, often leading to wellbore collapse, shrinkage, and sticking, and other downhole complex accidents, significantly increasing drilling time and cost. According to statistics, 75% of wellbore instability problems mainly occur in shale formations, especially in water-sensitive formations. The clay mineral content in shale formations is high, and when in contact with external fluids, it is prone to hydration, leading to wellbore instability. Oil-based drilling fluids are widely used in such formations due to their good wellbore stability and strong inhibition. However, oil-based drilling fluids have serious environmental pollution problems, are difficult to dispose of, and are costly. Therefore, developing water-based drilling fluids with comparable effects to oil-based drilling fluids to replace oil-based drilling fluids has become a trend in current drilling fluid technology development, which is particularly important in shale gas development. Shale gas horizontal wells have long horizontal sections, and the contact time between drilling fluids and formations is greatly increased, making shale hydration problems more serious and wellbore instability more prominent.

[0003] For decades, researchers have been working to solve the problem of clay swelling, and have developed various clay hydration inhibitors. Existing clay hydration inhibitors mainly include inorganic salts, formate salts, polymers, bitumen, sugars and their derivatives, glycerol, ethylene glycol, silicates, etc. For example, a clay mineral surface hydration intercalation inhibitor and its preparation method and application are disclosed in Chinese Patent No. CN114395380A, and the inhibitor is a compound of formula (I):

[0004]

[0005] However, these inhibitors can inhibit clay mineral hydration to some extent, but their application in high water-sensitive formations has not been completely successful, and they cannot completely inhibit the surface hydration of clay minerals. In particular, when clay minerals come into contact with external fluids, the surface hydration capacity is very strong, with a hydration pressure of up to 400 MPa, making it extremely difficult to inhibit and remove. Moreover, the polyamine inhibitors currently studied and applied are mostly linear structures. For linear polyamine inhibitors, they usually have a random linear configuration after dissolving in water, and when they are used in shale gas drilling, the winding and coating on clay are uneven, which can easily cause repeated adsorption or no adsorption. SUMMARY

[0006] In view of the problems in the prior art, the clay mineral surface hydration intercalation inhibitor for drilling fluid and a preparation method and application thereof are provided, so that the technical problem that the clay hydration inhibitor in the prior art cannot completely inhibit the surface hydration of clay minerals is solved.

[0007] The present application is realized by the following technical solutions:

[0008] The clay mineral surface hydration intercalation inhibitor for drilling fluid comprises a compound of formula A with the following structure:

[0009] ;

[0010] Preferably, n1 and n2 are each independently selected from an integer from 10 to 150.

[0011] R1 is selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C3-C16 cycloalkyl, substituted or unsubstituted C5-C14 aryl, substituted or unsubstituted 3-16 membered heterocyclyl, or substituted or unsubstituted 5-14 membered heteroaryl.

[0012] Ar1 is selected from substituted or unsubstituted C3-10 cycloalkyl, substituted or unsubstituted C5-C14 aryl, substituted or unsubstituted 3-10 membered heterocyclyl, or substituted or unsubstituted 5-10 membered heteroaryl.

[0013] Preferably, R1 is selected from substituted or unsubstituted C1-C5 alkyl, substituted or unsubstituted C2-C5 alkenyl, substituted or unsubstituted C2-C5 alkynyl, substituted or unsubstituted C1-C5 alkoxy, substituted or unsubstituted C3-10 cycloalkyl, substituted or unsubstituted C5-C12 aryl, substituted or unsubstituted 3-10 membered heterocyclyl, or substituted or unsubstituted 5-10 membered heteroaryl.

[0014] Preferably, R1 is selected from methyl, ethyl or phenyl; the methyl, ethyl or phenyl is optionally substituted with one or more C1-C3 alkyl, amino, nitro or hydroxyl.

[0015] Preferably, Ar1 is selected from substituted or unsubstituted C5-C14 aryl.

[0016] Preferably, Ar1 is selected from 、 or .

[0017] Preferably, n1 and n2 are each independently selected from an integer from 10 to 150.

[0018] Preferably, the intercalation inhibitor comprises at least one of a compound of formula A-1, a compound of formula A-2 or a compound of formula A-3 having the following structure:

[0019]

[0020]

[0021] Preferably, the mass percentage of the compound of formula A is 0.5% to 5% based on the total mass of the intercalation inhibitor.

[0022] The preparation method of the clay mineral surface hydration intercalation inhibitor for drilling fluid described above comprises the following steps:

[0023] Step 1: dissolve a polymer containing a secondary amine group in an organic solvent to obtain a reaction solution;

[0024] Step 2: add an organic tin catalyst to the reaction solution, stir until uniform, then add an isocyanate compound, continue to stir and react to obtain the compound of formula A.

[0025] The application of the clay mineral surface hydration intercalation inhibitor for drilling fluid described above in inhibiting the surface hydration of clay minerals.

[0026] Compared with the prior art, the present application has the following beneficial technical effects:

[0027] The clay mineral surface hydration intercalation inhibitor for drilling fluid in the present application comprises a compound of formula A having the following structure, which comprises an I-A part, an I-B part and an I-C part:

[0028] ​​​wherein I-A portion contains two -NH- groups, which have good hydrophilicity; are beneficial to form hydrogen bonds with water molecules between silicate layers in clay minerals; Ar1 is selected from substituted or unsubstituted C3-10 cycloalkyl, substituted or unsubstituted C5-C14 aryl, substituted or unsubstituted 3-10 membered heterocyclyl, or substituted or unsubstituted 5-10 membered heteroaryl, and these cycloalkyl, aryl, heterocyclyl or heteroaryl, especially aryl or heteroaryl, have planar structures which are beneficial to be inserted into the interlayer structure of silicate in a monolayer paving form, in addition, the charge distribution of the aryl group is changed due to the connection with the amide group, thereby facilitating the insertion into the interlayer structure of silicate, achieving the purpose of "intercalation". I-B portion and I-C portion contain tertiary amine groups with certain hydrophilic ability and R1 groups with hydrophobic ability; therefore, after I-A portion completes intercalation, I-B portion and I-C portion can form hydrogen bonds with water molecules between silicate layers in clay minerals due to the presence of tertiary amine groups, and the R1 groups with hydrophobic ability can prevent water molecules from penetrating and swelling on the surface of clay minerals. Therefore, I-A portion can prevent the swelling of the crystal layer of clay minerals from hydration and swelling, and I-B portion and I-C portion can prevent the penetration and swelling of clay minerals from hydration and swelling by intercalation of I-A portion and the hydrophilic-hydrophobic characteristics of themselves. DETAILED DESCRIPTION

[0029] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings to those skilled in the art of the present application, and in case of conflict, the definitions in the specification shall prevail.

[0030] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting on the scope of the present application, i.e., the present application can be implemented without regard to any particular theory or mechanism.

[0031] Herein, all features defined in the form of numerical ranges or percentage ranges such as values, amounts, contents and concentrations are for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0032] Herein, unless otherwise specified, "comprise", "include", "contain", "have" or similar words encompass the meaning of "consist of" and "consist essentially of", for example, "A comprises a" encompasses the meaning of "A comprises a and other" and "A comprises only a".

[0033] Herein, all possible combinations between technical features in various embodiments or examples are not described in order to make the description concise. Therefore, as long as there is no contradiction in the combination of technical features, various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations shall be considered as the scope disclosed in the specification.

[0034] The present application provides a clay mineral surface hydration intercalation inhibitor for drilling fluid, the intercalation inhibitor comprising a compound of Formula A having the following structure:

[0035]

[0036] wherein n1 and n2 are each independently selected from an integer from 1 to 200;

[0037] R1 is selected from substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C3-C16 cycloalkyl, substituted or unsubstituted C5-C14 aryl, substituted or unsubstituted 3-16 membered heterocyclyl, or substituted or unsubstituted 5-14 membered heteroaryl;

[0038] Ar1 is selected from substituted or unsubstituted C3-10 cycloalkyl, substituted or unsubstituted C5-C14 aryl, substituted or unsubstituted 3-10 membered heterocyclyl, or substituted or unsubstituted 5-10 membered heteroaryl.

[0039] In an aspect of the embodiments of the present disclosure, preferably, n1 and n2 are each independently selected from an integer from 10 to 150.

[0040] In an aspect of the embodiments of the present disclosure, preferably, R1 is selected from substituted or unsubstituted C1-C5 alkyl, substituted or unsubstituted C2-C5 alkenyl, substituted or unsubstituted C2-C5 alkynyl, substituted or unsubstituted C1-C5 alkoxy, substituted or unsubstituted C3-10 cycloalkyl, substituted or unsubstituted C5-C12 aryl, substituted or unsubstituted 3-10 membered heterocyclyl, or substituted or unsubstituted 5-10 membered heteroaryl.

[0041] In an aspect of the embodiments of the present disclosure, preferably, R1 is selected from methyl, ethyl or phenyl; the methyl, ethyl or phenyl is optionally substituted by one or more C1-C3 alkyl, amino, nitro or hydroxyl.

[0042] In an aspect of the embodiments of the present disclosure, further specifically, R1 is selected from ethyl.

[0043] In an aspect of the embodiments of the present disclosure, the compound of formula A has the following structural formula:

[0044]

[0045] In an aspect of the embodiments of the present disclosure, specifically, Ar1 is selected from substituted or unsubstituted C5-C14 aryl;

[0046] In an aspect of the embodiments of the present disclosure, specifically, Ar1 is selected from , or .

[0047] In an aspect of the embodiments of the present disclosure, n1 and n2 have equal values.

[0048] In an aspect of the embodiments of the present disclosure, specifically, the intercalation inhibitor comprises at least one of a compound of formula A-1, a compound of formula A-2 or a compound of formula A-3 having the following structure:

[0049]

[0050]

[0051] wherein n1 and n2 are each independently selected from an integer from 1 to 200.

[0052] In an aspect of the embodiments of the present disclosure, the intercalation inhibitor further comprises water; and the mass percentage of the compound of formula A is 0.5% to 5% based on the total mass of the intercalation inhibitor.

[0053] In an aspect of the embodiments of the present disclosure, preferably, the mass percentage of the compound of formula A is 0.5% to 1.5% based on the total mass of the intercalation inhibitor. Specifically, the mass percentage of the compound of formula A is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5% based on the total mass of the intercalation inhibitor.

[0054] In an aspect of the embodiments of the present disclosure, the intercalation inhibitor further comprises one or more of an emulsifier, a plugging agent, a weighting agent, a tackifier, a lubricant, a viscosity reducer, a fluid loss additive or a flocculant.

[0055] In an aspect of the embodiments of the present disclosure, the emulsifier is selected from one or more of Span, Tween, OP, NP and AEO; and the HLB value of the emulsifier is selected from 1 to 10.

[0056] Span: Span series emulsifiers, also known as sorbitan fatty acid esters, are a class of non-ionic surfactants. They are prepared by esterification of sorbitol and its anhydride with various fatty acids. Depending on the fatty acid, there are Span-20, Span-40, Span-60, Span-80, and other models. Different models of Span emulsifiers have different HLB values and are widely used in water-in-oil emulsion systems.

[0057] Tween: Tween series emulsifiers are polyoxyethylene sorbitan fatty acid esters, also belonging to non-ionic surfactants. They are the product of the reaction of Span emulsifiers with ethylene oxide, and can form good emulsification effects when used with Span emulsifiers. Common models include Tween-20, Tween-40, Tween-60, Tween-80, etc., and are generally used in oil-in-water emulsion systems.

[0058] OP: OP series emulsifiers are alkyl phenol polyoxyethylene ether non-ionic surfactants, such as OP-10, which have good emulsification, wetting, and dispersion properties, and are widely used in chemical, textile, and daily chemical industries.

[0059] NP: NP series emulsifiers are also alkyl phenol polyoxyethylene ethers, similar to OP series, but may have some differences in structure and application performance. They are also non-ionic surfactants commonly used for emulsification and solubilization.

[0060] AEO: AEO is the English abbreviation for fatty alcohol polyoxyethylene ether, which is a non-ionic surfactant. It is prepared by addition reaction of fatty alcohol and ethylene oxide, and has various product types according to the length of the fatty alcohol carbon chain and the number of ethylene oxide additions. It is used as an emulsifier, cleaning agent, etc. in the detergent, textile, and cosmetic industries.

[0061] The HLB value of emulsifiers, i.e. Hydrophile-Lipophile Balance, is an index for measuring the balance between the hydrophilic and lipophilic groups in the surfactant molecule.

[0062] In one aspect of the present disclosure, the mass percentage content of the emulsifier can be selected from 0.02% to 0.5%, based on the total mass of the intercalation inhibitor. Specifically, the mass percentage content of the emulsifier can be selected from 0.02%, 0.05%, 0.08%, 0.1%, 0.2%, 0.25%, 0.3%, 0.4%, or 0.5%, based on the total mass of the intercalation inhibitor.

[0063] In an aspect of the embodiments of the present disclosure, the plugging agent can be selected from asphalt, sulfonated asphalt, nano-silica or nano-barite; but not limited thereto, other choices commonly used in the art can be used.

[0064] In an aspect of the embodiments of the present disclosure, the mass percentage content of the plugging agent can be selected from 0.01% to 0.2%, based on the total mass of the intercalation inhibitor; specifically, the mass percentage content of the plugging agent can be selected from 0.01%, 0.02%, 0.05%, 0.08%, 0.1% or 0.2%, based on the total mass of the intercalation inhibitor.

[0065] In an aspect of the embodiments of the present disclosure, the weighting agent can be selected from barite and / or iron ore powder; but not limited thereto, other choices commonly used in the art can be used.

[0066] In an aspect of the embodiments of the present disclosure, the mass percentage content of the weighting agent can be selected from 0.5% to 5%, based on the total mass of the intercalation inhibitor; specifically, the mass percentage content of the plugging agent can be selected from 0.5%, 0.75%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75%, 3%, 3.5%, 4%, 4.5% or 5%, based on the total mass of the intercalation inhibitor.

[0067] In an aspect of the embodiments of the present disclosure, the lubricant can be selected from non-ionic surfactants; but not limited thereto, other choices commonly used in the art can be used.

[0068] In an aspect of the embodiments of the present disclosure, the mass percentage content of the lubricant can be selected from 0.25% to 3%, based on the total mass of the intercalation inhibitor; specifically, the mass percentage content of the plugging agent can be selected from 0.25%, 0.5%, 0.75%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75% or 3%, based on the total mass of the intercalation inhibitor.

[0069] In an aspect of the embodiments of the present disclosure, the fluid loss additive can be selected from one or a mixture of several of the Carboxymethyl Cellulose (CMC) series, the Polyacrylic Acid (PAC) series, the Sulfonated Phenol-Formaldehyde Resin (SMP) series, the Hydrolyzed Polyacrylonitrile Salt (HPAN) series, and the Acrylate Salt (SK) series, but is not limited thereto, and other alternatives commonly used in the art can be used.

[0070] In an aspect of the embodiments of the present disclosure, the percentage by mass of the fluid loss additive based on the total mass of the intercalation inhibitor can be selected from 0.3% to 5%, and specifically, the percentage by mass of the fluid loss additive based on the total mass of the intercalation inhibitor can be selected from 0.3%, 0.5%, 0.75%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75%, 3%, 3.5%, 4%, 4.5%, or 5%.

[0071] In an aspect of the embodiments of the present disclosure, the viscosity reducer can be selected from one or a mixture of several of sulfomethyl tannin, sulfomethyl tannin extract, sulfonated styrene-maleic anhydride copolymer, and vinyl acetate-maleic anhydride copolymer, but is not limited thereto, and other alternatives commonly used in the art can be used.

[0072] In an aspect of the embodiments of the present disclosure, the percentage by mass of the viscosity reducer based on the total mass of the intercalation inhibitor can be selected from 0.3% to 5%, and specifically, the percentage by mass of the viscosity reducer based on the total mass of the intercalation inhibitor can be selected from 0.3%, 0.5%, 0.75%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75%, 3%, 3.5%, 4%, 4.5%, or 5%.

[0073] In an aspect of the embodiments of the present disclosure, the flocculating agent can be selected from one or a combination of several of acrylonitrile copolymer potassium salt, acrylamide and sodium acrylate copolymer, and a complex ionic high molecular weight polymer, but is not limited thereto, and other alternatives commonly used in the art can be used.

[0074] In one aspect of the embodiments of the present disclosure, the mass percentage of the flocculating agent based on the total mass of the intercalation inhibitor can be selected from 0.2% to 3.5%; specifically, the mass percentage of the flocculating agent based on the total mass of the intercalation inhibitor can be selected from 0.2%, 0.3%, 0.5%, 0.75%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75%, 3% or 3.5%.

[0075] In one aspect of the embodiments of the present disclosure, the viscosity increasing agent can be selected from one or a combination of several of high-viscosity cationic cellulose, high-viscosity sodium carboxymethyl cellulose, acrylic acid salt and acrylamide copolymer, and hydroxyethyl cellulose; but not limited thereto, other options commonly used in the art can be used.

[0076] In one aspect of the embodiments of the present disclosure, the mass percentage of the viscosity increasing agent based on the total mass of the intercalation inhibitor can be selected from 0.3% to 5%; specifically, the mass percentage of the viscosity increasing agent based on the total mass of the intercalation inhibitor can be selected from 0.3%, 0.5%, 0.75%, 1.0%, 1.25%, 1.5%, 1.75%, 2.0%, 2.25%, 2.5%, 2.75%, 3%, 3.5%, 4%, 4.5% or 5%.

[0077] In one aspect of the embodiments of the present disclosure, the compound of formula A can be prepared by the following steps:

[0078] Step 1: dissolving a polymer containing a secondary amine group in an organic solvent to obtain a solution with a solid content of 10% to 30%; preferably, a solution with a solid content of 10% to 25% is obtained;

[0079] Step 2: adding an organic tin catalyst to the solution obtained in Step 1, stirring until uniform, then adding an isocyanate compound, continuing to stir for 45 to 90 minutes to obtain the compound of formula A.

[0080] In one aspect of the embodiments of the present disclosure, the compound of formula A-1, the compound of formula A-2 or the compound of formula A-3 is prepared by the following steps:

[0081] Step 1: dissolving polyethyleneimine in an organic solvent to obtain a solution with a solid content of 10% to 30%;

[0082] Step 2: adding an organic tin catalyst to the solution obtained in Step 1, stirring until uniform, then adding an isocyanate compound, continuing to stir for 45 to 90 minutes to obtain the compound of formula A-1, the compound of formula A-2 or the compound of formula A-3.

[0083] When the isocyanate compound is 1,5-naphthalene diisocyanate, a compound of Formula A-1 is obtained; when the isocyanate compound is diphenylmethane diisocyanate, a compound of Formula A-2 is obtained; and when the isocyanate compound is dimethyl diphenyl diisocyanate, a compound of Formula A-3 is obtained.

[0084] In one aspect of the embodiments of the present disclosure, the mass ratio of the isocyanate compound and the polyethyleneimine is selected from 1 to 15: 100.

[0085] In one aspect of the embodiments of the present disclosure, the average polymerization degree of the polyethyleneimine is selected from 5 to 50; preferably, the average polymerization degree of the polyethyleneimine is 7.

[0086] In one aspect of the embodiments of the present disclosure, the organic solvent is at least one selected from dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl sulfoxide, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0087] In one aspect of the embodiments of the present disclosure, the organic tin catalyst is any one selected from dibutyltin dilaurate, stannous octoate, bis(dodecylthio)dibutyltin, butyltin trichloride, monobutyltin oxide, dibutyltin oxide, and dibutyltin diacetate.

[0088] In one aspect of the embodiments of the present disclosure, the mass of the added organic tin catalyst is 0.1% to 0.5% of the mass of the polyethyleneimine.

[0089] According to a second aspect of the embodiments of the present disclosure, there is provided the use of the aforementioned intercalation inhibitor for inhibiting the hydration of the surface of a clay mineral.

[0090] The present application is further described in conjunction with the following examples. It should be understood that these examples are intended to illustrate the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that various modifications and changes can be made to the present application by those skilled in the art upon reading the contents of the present application, and such equivalent forms are also within the scope of the appended claims.

[0091] The following examples use the apparatuses and devices that are conventional in the art. The experimental methods in the following examples, unless otherwise specified, are generally performed according to the conventional conditions, or according to the conditions suggested by the manufacturers. The following examples use various raw materials, unless otherwise specified, all of which are conventional commercially available products, and the specifications thereof are conventional in the art. In the specification of the present application and the following examples, unless otherwise specified, "%" means weight percent, "parts" means weight parts, and the ratio means weight ratio.

[0092] The list of items connected by "at least one of," "at least one," "at least one of the," or other similar phrases can mean any combination of the listed items. For example, if A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or A, B, and C. Item A can include a single component or multiple components. Item B can include a single component or multiple components. Item C can include a single component or multiple components.

[0093] In the present disclosure, the term "alkyl" refers to an aliphatic hydrocarbon group that can be straight-chain or branched. Branched is meant one or more lower alkyl groups, such as methyl, ethyl, or propyl, attached to the linear alkyl chain. "Lower alkyl" refers to a group that contains from about 1 to about 6 carbon atoms in the chain, which can be straight-chain or branched.

[0094] In the present disclosure, the term "alkenyl" refers to an aliphatic hydrocarbon group that contains at least one carbon-carbon double bond, which can be straight-chain or branched. Branched is meant one or more lower alkyl groups, such as methyl, ethyl, or propyl, attached to the linear alkenyl chain. "Lower alkenyl" refers to a group that contains from about 2 to about 6 carbon atoms in the chain, which can be straight-chain or branched.

[0095] In the present disclosure, the term "alkynyl" refers to an aliphatic hydrocarbon group that contains at least one carbon-carbon triple bond, which can be straight-chain or branched. Branched is meant one or more lower alkyl groups, such as methyl, ethyl, or propyl, attached to the linear alkynyl chain. "Lower alkynyl" refers to a group that contains from about 2 to about 6 carbon atoms in the chain, which can be straight-chain or branched. Non-limiting examples of alkynyl groups include ethynyl, propynyl, 2-butynyl, 3-methylbutynyl, n-pentynyl, and decynyl.

[0096] In the present disclosure, the term "aryl" refers to an aromatic monocyclic or polycyclic ring system. The aryl group can be optionally substituted with one or more "ring system substituents," which can be the same or different, as defined herein. Non-limiting examples of suitable aryl groups include phenyl and naphthyl.

[0097] In the present disclosure, the term "heteroaryl" refers to an aromatic monocyclic or polycyclic ring system in which one or more ring atoms are an element other than carbon, such as nitrogen, oxygen, or sulfur, alone or in combination, preferably the heteroaryl contains from about 5 to about 6 ring atoms. The "heteroaryl" can be optionally substituted with one or more "ring system substituents," which can be the same or different, as defined herein. The prefix naphtho-, oxazepino-, or thiazepino- before a heteroaryl root name indicates the presence of at least one nitrogen, oxygen, or sulfur atom, respectively, as a ring atom. The nitrogen atom of a heteroaryl group can optionally be oxidized to the corresponding N-oxide. Non-limiting examples of suitable heteroaryl groups include pyridyl, pyrazinyl, furanyl, thiophenyl, pyrimidinyl, isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, pyrazolyl, furazanyl, pyrrolyl, pyrazolyl, triazolyl, 1,2,4-thiadiazolyl, pyrazinyl, pyridazinyl, quinoxalinyl, phthalazinyl, imidazo[l,2-a]pyridyl, imidazo[2,l-b]thiazolyl, benzofurazanyl, indolyl, azaindolyl, benzimidazolyl, benzothiophenyl, quinolinyl, imidazolyl, thienopyridyl, quinazolinyl, thienopyrimidinyl, pyrrolopyridyl, imidazopyridyl, isoquinolinyl, benzoazaindolyl, 1,2,4-triazinyl, benzothiazolyl, and the like.

[0098] In the present disclosure, the term "amino" refers to a -NR'R" group. The amino group can be optionally substituted. In an unsubstituted amino group, R' and R" are hydrogen. In a substituted amino group, R' and R" can each independently be, but are not limited to, hydrogen, alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, alkylcycloalkyl, alkylheterocycloalkyl, alkoxy, sulfonyl, alkenyl, alkylcarbonyl, aryl, arylalkyl, or heteroaryl, provided that R' and R" are not both hydrogen. In a substituted amino group, R' and R" can cyclize to form a cyclic amino group, such as pyrrolidinyl or piperidinyl. Such cyclic amino groups can incorporate additional heteroatoms, such as to form a piperazinyl or morpholinyl group. Such cyclic amino groups can be optionally substituted, such as with an amino, hydroxyl, or oxo group.

[0099] In the present disclosure, the term "alkoxy" refers to -O-alkyl. Alkoxy can refer to a straight, branched, or cyclic, saturated or unsaturated, oxy-hydrocarbon chain, including, for example, methoxy, ethoxy, propyloxy, isopropoxy, butoxy, t-butoxy, and pentoxy. Alkoxy can be optionally substituted with one or more alkoxy substituents ("substituted alkoxy").

[0100] In the present disclosure, the term "cycloalkyl" refers to a non-aromatic mono- or polycyclic ring system, preferably cycloalkyl rings contain from about 5 to about 7 ring atoms. Cycloalkyl groups can be optionally substituted with one or more "ring system substituents" which can be the same or different, as defined above. Non-limiting examples of suitable monocyclic cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like. Non-limiting examples of suitable polycyclic cycloalkyl groups include 1-decalinyl, norbornanyl, adamantyl, and the like. In the present disclosure, the term "cycloalkoxy" refers to a group in which one or more of the carbon atoms of a mono- or polycyclic ring system of "cycloalkyl" is replaced with an oxygen atom.

[0101] In the present disclosure, the term "heterocyclyl" refers to a non-aromatic saturated monocyclic or polycyclic ring system in which one or more ring atoms of the ring system is an element other than carbon, such as nitrogen, oxygen, or sulfur, alone or in combination. There are no adjacent oxygen and / or sulfur atoms in the ring system, and preferred heterocycles contain from about 5 to about 6 ring atoms. The prefix n-, o-, or s- before the root name of a heterocyclyl group indicates the presence of at least one nitrogen, oxygen, or sulfur atom, respectively, as a ring atom. Heterocyclyl groups can be optionally substituted with one or more "ring system substituents" which can be the same or different, as defined herein. The nitrogen or sulfur atom of a heterocyclyl group can be optionally oxidized to the corresponding N-oxide, S-oxide, or S,S-dioxide. Non-limiting examples of suitable monocyclic heterocyclyl rings include piperidinyl, pyrrolidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, 1,3-dioxolanyl, 1,4-dioxanyl, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, and the like.

[0102] In the present disclosure, "hydration of clay mineral surface" includes surface hydration and osmotic hydration; wherein surface hydration is the hydration film of 1-4 layers of water molecules formed between the silicate layers of clay minerals. Osmotic hydration is the diffusion of exchangeable cations adsorbed on the surface of clay mineral layers into the water phase to form a diffuse double layer, forming a diffuse double layer between clay minerals, and the hydration effect caused by the combined action of double layer repulsion and osmotic pressure.

[0103] Therefore, in the art, the hydration swelling of clay minerals is divided into two stages: crystal layer swelling and osmotic swelling; wherein, the crystal layer swelling is mainly caused by the surface hydration of the crystal layer of the clay mineral and the hydration of the interlayer cations. With the increase of the relative humidity in the environment, the content of the interlayer water of the clay mineral increases from zero to about four water molecular layers, the interlayer spacing of the clay mineral increases stepwise (discontinuous) with the increase of the number of interlayer water molecular layers, and the swelling pressure decreases with the increase of the number of water molecular layers; when the interlayer cations are fully hydrated and separated from the surface of the clay mineral to form a diffuse double layer, the crystal layer swelling ends and the osmotic swelling begins, and due to the repulsion of the double layer, the crystal layer of the clay mineral is further pushed away, so that the interlayer spacing of the clay mineral increases sharply until it is completely dispersed. The traditional description of the crystal layer swelling of the clay mineral uses "1-layer hydration", "2-layer hydration" and "multi-layer hydration" to describe the step-by-step expansion or contraction of the interlayer spacing.

[0104] In the present disclosure, "intercalation" refers to the reversible insertion of guest molecules into a layered host structure and retaining the structural characteristics of the host; the intercalation of clay minerals containing various natural layered silicates has the following characteristics: (1) containing water and organic substances between the layers; (2) can be converted from a hydrophilic state to a hydrophobic state; (3) exhibits a certain acidity; (4) exists in the form of being exchanged by various inorganic or organic cations.

[0105] Therefore, in the art, for the layered structure, the following points should be considered for the organic derivatives as potential intercalating agents: (1) the organic groups belong to two adjacent crystal layers, rather than penetrating each other. In this way, there is less steric hindrance for the diffusion of the organic groups in the interlayer region; (2) the force between the adjacent crystal layers is expected to be van der Waals force or hydrogen bond.

[0106] The present disclosure provides a compound of formula A having the following structure, the compound of formula A comprising an I-A moiety, an I-B moiety, and an I-C moiety:

[0107]

[0108] The I-A part contains two -NH- groups, which have good hydrophilicity, and are beneficial to form hydrogen bonds with water molecules between the silicate layers of clay minerals; Ar1 is selected from aromatic groups with planar structures, which are beneficial to be inserted into the interlayer structure of silicates in the form of monolayer paving, and in addition, the charge distribution of the aromatic group is changed due to the connection with the amide group, thereby facilitating the insertion into the interlayer structure of silicates to achieve the purpose of "intercalation". The I-B part and the I-C part contain tertiary amine groups with certain hydrophilic ability and R1 groups with hydrophobic ability; therefore, after the I-A part completes the intercalation, the I-B part and the I-C part can form hydrogen bonds with water molecules between the silicate layers of clay minerals due to the presence of the tertiary amine group, and the R1 group with hydrophobic ability can prevent water molecules from penetrating and swelling on the surface of the clay mineral. Therefore, the I-A part can prevent the crystal layer of the clay mineral from swelling due to hydration and swelling, and the I-B part and the I-C part can prevent the penetration and swelling of the clay mineral due to hydration and swelling by the intercalation of the I-A part and the hydrophilic and hydrophobic properties of the I-B part and the I-C part.

[0109] In the present disclosure, polyethyleneimine with a molecular weight of 300 is selected as the raw material; the degree of polymerization of the polyethyleneimine with a molecular weight of 300 is about 7.

[0110] In the present disclosure, when Ar1 is selected from naphthyl, its structure is most beneficial to be inserted into the interlayer structure of silicates in the form of monolayer paving.

[0111] The present application will be further described in the manner of specific examples. The various chemical reagents used in the examples of the present application are obtained through conventional commercial channels unless otherwise specified. The contents described below are mass contents unless otherwise specified. It is understood that the operations are carried out at room temperature unless otherwise specified.

[0112] The present application will be further described in the manner of specific examples. The various chemical reagents used in the examples of the present application are obtained through conventional commercial channels unless otherwise specified. The contents described below are mass contents unless otherwise specified. It is understood that the operations are carried out at room temperature unless otherwise specified.

[0113] Example 1

[0114] A preparation method of a clay mineral surface hydration intercalation inhibitor for drilling fluid, comprising the following steps:

[0115] 100 parts by weight of polyethylene imine with a degree of polymerization of 300 was dissolved in 500 parts by weight of the organic solvent dimethylformamide; then 0.15 parts by weight of dibutyltin dilaurate was added as a catalyst, mixed under magnetic stirring for 15 min, then 0.75 parts by weight of carboxymethyl cellulose, 0.06 parts by weight of Span 80, 0.6 parts by weight of sulfomethyl tannin were added, stirred for 30 min, then 75 parts by weight of 1,5-naphthalene diisocyanate was added, and stirring was continued for 80 min. After the reaction was completed, the organic solvent was removed by rotary evaporation, and then freeze-drying was performed to obtain the intercalation inhibitor of Example 1, the structure of which is shown below:

[0116]

[0117] Example 2

[0118] A method for preparing a clay mineral surface hydration intercalation inhibitor for drilling fluid, comprising the following steps:

[0119] 100 parts by weight of polyethylene imine with a degree of polymerization of 300 was dissolved in 500 parts by weight of the organic solvent dimethylformamide; then 0.15 parts by weight of dibutyltin dilaurate was added as a catalyst, mixed under magnetic stirring for 15 min, then 0.75 parts by weight of carboxymethyl cellulose, 0.06 parts by weight of Span 80, 0.6 parts by weight of sulfomethyl tannin were added, stirred for 30 min, then 80 parts by weight of diphenylmethane diisocyanate was added, and stirring was continued for 80 min. After the reaction was completed, the organic solvent was removed by rotary evaporation, and then freeze-drying was performed to obtain the intercalation inhibitor of Example 2, the structure of which is shown below:

[0120]

[0121] Example 3

[0122] A method for preparing a clay mineral surface hydration intercalation inhibitor for drilling fluid, comprising the following steps:

[0123] 100 parts by weight of polyethylene imine with a degree of polymerization of 300 was dissolved in 500 parts by weight of the organic solvent dimethylformamide; then 0.15 parts by weight of dibutyltin dilaurate was added as a catalyst, mixed under magnetic stirring for 15 min, then 0.75 parts by weight of carboxymethyl cellulose, 0.06 parts by weight of Span 80, 0.6 parts by weight of sulfomethyl tannin were added, stirred for 30 min, then 85 parts by weight of dimethyl diphenyl diisocyanate was added, and stirring was continued for 80 min. After the reaction was completed, the organic solvent was removed by rotary evaporation, and then freeze-drying was performed to obtain the intercalation inhibitor of Example 3, the structure of which is shown below:

[0124]

[0125] Comparative Example 1

[0126] Comparative Example 1 includes the following steps:

[0127] 100 parts by weight of polyethyleneimine with a degree of polymerization of 300, 0.75 parts by weight of carboxymethyl cellulose, 0.06 parts by weight of Span 80, 0.6 parts by weight of sulfomethyl tannin, 75 parts by weight of 1,5-naphthalene diisocyanate were added to 500 parts by weight of the organic solvent dimethylformamide, stirred for 80 min, the organic solvent was removed by rotary evaporation, and then freeze-drying was performed to obtain the intercalation inhibitor of Comparative Example 1.

[0128] Performance detection, test of interlayer spacing and test of water absorption:

[0129] Test of interlayer spacing: the samples of Examples 1-3 and Comparative Example 1 were respectively configured into 2% aqueous inhibitor solutions; the sodium montmorillonite was oven-dried at 150°C to a constant weight, and then divided into 4 portions, which were respectively added to the aqueous inhibitor solutions configured by Examples 1-3 and Comparative Example 1 and stirred for 24 h, then the suspension was taken out and introduced into a centrifuge tube, centrifuged at 4000 rpm for 10 min, the supernatant was poured out to obtain the precipitate, and the lower precipitate sample was directly subjected to X Ray diffraction analysis: according to the Bragg equation, the interlayer spacing of sodium bentonite in different experimental slurries was determined; the remaining precipitate was vacuum-dried at 80°C, and then placed at room temperature for 72 h under different humidity conditions to test the unit adsorbed water amount. The results are shown in Table 1. As can be seen from Table 1, the clay mineral surface hydration intercalation inhibitor for drilling fluid in the examples has a significant advantage in inhibiting the surface hydration of clay minerals compared with Comparative Example 1 and untreated sodium montmorillonite. Specifically, the interlayer spacing of the clay treated by the samples of Examples 1-3 is significantly smaller than that of Comparative Example 1 and untreated sodium montmorillonite, which indicates that the inhibitor in the examples more effectively limits the expansion of the crystal layer of the clay mineral. Meanwhile, the water absorption of Examples 1-3 is also significantly lower than that of Comparative Example 1 and untreated sodium montmorillonite under the conditions of relative humidity of 40%, 60% and 80%, which indicates that the inhibitor in the examples effectively reduces the osmotic hydration of the clay mineral. These data collectively prove that the clay mineral surface hydration intercalation inhibitor for drilling fluid provided by the present application can effectively inhibit the surface hydration of the clay mineral, solving the technical problem that the clay hydration inhibitor in the prior art cannot completely inhibit the surface hydration of the clay mineral.

[0130] Table 1

[0131]

[0132] Finally, it should be noted that the above examples are merely intended to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. Use of a clay mineral surface hydration intercalation inhibitor for a drilling fluid in the inhibition of clay mineral surface hydration, characterized in that, The intercalation inhibitor comprises at least one of a compound of Formula A-1, a compound of Formula A-2, or a compound of Formula A-3 having the following structure: 、 、 ； n1 and n2 are both 300.

2. The use of the clay mineral surface hydration intercalation inhibitor for a drilling fluid according to claim 1, characterized by, The mass percentage content of the compound of Formula A-1, the compound of Formula A-2, or the compound of Formula A-3 is 0.5% to 5% based on the total mass of the intercalation inhibitor.

Images